This invention relates to compositions containing poly (arylene sulfide). In one of its aspects this invention relates to molding compositions suitable for encapsulating semiconductor chips. In another of its aspects this invention relates to a method for preparing compositions suitable for use in encapsulating semiconductor chips. In still another aspect of the invention it relates to a molded composition containing poly (arylene sulfide) encapsulating a semiconductor chip.
There are several different polymers that are known to be useful in molding processes for the encapsulation of electronic parts. Up until this time poly (arylene sulfide) has not been known as useful in compositions that can be used for molding in the encapsulation of semiconductor parts.
In the development of a poly (arylene sulfide) based compound for use in encapsulating semiconductor chips for the electronics industry, three key properties had to be built into the resin: (1) High melt flow to insure easy fill of the multicavity mold, (2) low wash-out or short circuiting of the one mil whiskers which connect the internal components with the outside terminals, and (3) low coefficient of thermal expansion to prevent the resin from cracking after being injection molded onto the heavy metal lead frames that support the multicomponent chips. To achieve these properties a balance had to be struck between the various components used along with the poly (arylene sulfide) in the composition.
It is therefore an object of this invention to provide a composition containing poly (arylene sulfide) that is suitable for molding operations in the encapsulating of semiconductor chips for the electronics industry. It is another object of this invention to provide a method for preparing a composition suitable for molding operations in the encapsulating of semiconductor chips for the electronics industry. It is still another object of this invention to provide encapsulated semiconductor chips for the electronics industry.
Other aspects, objects and the various advantages of this invention will become apparent upon reading this specification and the attached claims.